For many larger building and insulation contractors, getting into the new- construction market means entering the supercompetitive world of fiberglass bidding, or going for high-end spray foam installations. Neither of these makes sense for a small company whose main focus is on cellulose and weatherization. Many small weatherization contractors are quick to offer the benefits of cellulose insulation to the existing-home market. When it comes to new construction, these same contractors can be just as quick to pass on the benefits of cellulose.